Ogasawarana yoshiwarana

Ogasawarana yoshiwarana
Conservation status
Critically Endangered[1]
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
(unranked):	clade Neritimorpha clade Cycloneritimorpha
Superfamily:	Helicinoidea
Family:	Helicinidae
Genus:	Ogasawarana
Species:	O. yoshiwarana
Binomial name
Helicina yoshiwarana (Pilsbry, 1902)[2]
Synonyms
Helicina yoshiwarana Pilsbry, 1902[2]

Ogasawarana yoshiwarana is a species of land snail with an operculum, a terrestrial gastropod mollusk in the family Helicinidae, the helicinids.

Description

Ogasawarana yoshiwarana was originally described under the name Helicina yoshiwarana by American malacologist Henry Augustus Pilsbry in 1902.^[2]

Pilsbry's original text (the type description) appeared in the key and it reads as follows:

“

Periphery more or less angular, or rounded though compressed. Surface delicately striate spirally. Alt. 3.5, diam. 5.3 to 5.8 mm.

”

Pilsbry also distinguished two variants:

• H. yoshiwarana var. arata - Upper surface strongly striate spirally.^[2]
• H. yoshiwarana var. mierotheca - Smaller, delicately striate. height of the shell is 2.2 mm. The width of the shell is 4.5 mm.^[2]

Distribution

This species was endemic to Haha-jima in the Ogasawara Islands (Japan).

Habitat

The ogasawarana yoshiwarana has been known to live (as lately as 2006) ^[1] on Higashizaki peninsula off the eastern coast of Hahajima, the second largest island in the Ogasawara Archipelago / Bonin Islands system. The Bonin Islands have been sometimes referred to as the Galapagos Islands of the Orient due to their highly diverse fauna and flora.^[3] The island is small and only partly covered by forest, which is where the terrestrial gastropod lives out its life.

Ecological role

This animal is essentially an herbivore, eating leaves, stems, soft bark, fruit, vegetables, fungi and algae. Its behavior is like any other land snail's: it thrives in damp and wet weather: Land Snails. This is especially true of the ogasawarana yoshiwarana because it lives in a subtropical/tropical environment. Predators of the species include predatory snails, ground beetles, leeches, and parasites.

Population and Conservation Status

Estimates of the population of this species haven't been conducted. They are expected to be found exclusively in this archipelago, not far from its endemic origin of Hahajima island. It is currently unknown why its population is sparse or even if it is declining or increasing in size. Habitat loss is not a factor; in fact, its home is one of the few places in the world not affected by anthropogenic forces or introduced non-native species. Perhaps the hand of natural selection plays a role in the specie's threatened status.

Extinction

Ogasawarana yoshiwarana is listed as critically endangered in the IUCN Red List of Threatened Species.^[4][5]

Last record of this species is from 1902 by type description by Henry Augustus Pilsbry.^[1] The species is considered to be critically endangered.^[1]

References

This article incorporates public domain text from reference.^[2]

1. ^ ^{a b c d} Chiba S., Davison A. & Mori H. (2007) "Endemic Land Snail Fauna (Mollusca) on a Remote Peninsula in the Ogasawara Archipelago, Northwestern Pacific". Pacific Science 61(2): 257–265. doi:10.2984/1534-6188(2007)61[257:ELSFMO]2.0.CO;2.
2. ^ ^{a b c d e f} Pilsbry H. A. (1902). "New land Mollusca from Japan and the Bonin Islands". Proceedings of the Academy of Natural Sciences of Philadelphia 54: 25-32. page 26.
3. ^ Yamaoka, Fumiko (May 12). "Saving an endangered bird in 'Orient's Galapagos'". The Japan Times
4. ^ Mollusc Specialist Group (1996). Ogasawarana yoshiwarana. 2006 IUCN Red List of Threatened Species. Downloaded on 7 August 2007.
5. ^ Mollusc Specialist Group (1996). Ogasawarana yoshiwarana. In: IUCN 2009. IUCN Red List of Threatened Species. Version 2009.2. <www.iucnredlist.org>. Downloaded on 28 February 2010.